AGA NEWS

The challenges of meeting increasing demand for livestock products with limiting resources prompted FAO to convene a one day symposium on Optimizing Feed Use Efficiency in Ruminant Animal Production Systems at the AAAP ANIMAL SCIENCE CONGRESS held in Bangkok from 26 to 30 November 2012. This symposium, attended by over 150 policymakers, scientists, extension workers and students, brought together renowned speakers from around the world to consider the need and strategies to improve the conversion of feed into human food by ruminant livestock. Salient points that emerged from the discussion are summarized below.

The increasing demand for food to feed the world’s growing population is relentless and the improved affluence being enjoyed by an increasing number of people results in higher demand for animal products: meat, eggs and milk. By 2050, the world will require an estimated additional 1305 million tonnes of grain, of which 40% would be used for feeding livestock. A major contributory factor to this extra demand is expected to be substantial increases in poultry and pig meat production. “A less food-competing route to increasing the supply of animal protein is to increase the production of ruminant animal products, utilizing forages and fibrous co-product feeds, as part of feeding systems designed to optimize rumen function and overall feed conversion efficiency,” said Prof. Margaret Gill.

Feed for producing milk or meat from livestock represents a major monetary cost for the farmer and a major resource cost for society. Average achieved efficiency of converting feed (Feed Conversion Efficiency; FCE) into milk or meat is considerably lower than what is possible with the genetic potential of many animals. This inevitably increases production costs and reduces the yield of milk or meat per unit of available feed, yet ruminants in particular can produce food from land unsuitable for crop production and using plant resources that do not compete with human food. The fundamental competitive advantage of ruminants – their ability to convert plant cell walls into milk or meat – must be better recognized. In contrast, previous genetic selection of animals has perpetuated the need for high nutrient density rations favouring increased cereal use, yet in many instances this has led to compromised rumen and animal health, poor product quality (low milk fat %) and reduced longevity. A significant realignment of animal genotype is needed to better match necessary changes in feed resource use whilst recognising the need for more realistic and sustainable measures of FCE achieved with increased forage/fibre use.

The importance of maternal beef cow performance in terms of achieved weaned calf weight against total feed consumed by the dam was stressed. With feed accounting for over 60% of the total costs of producing beef, it is important to match the maternal genotype to the prevailing nutritional and thermal environment. In the post-weaning phase optimization of FCE is important and in this context the potential to exploit a period of moderate feed restriction and the associated reduction in animal maintenance costs with enhanced performance due to a more advantageous composition of growth in the subsequent luxurious feeding phase is of particular relevance.

The importance of growth composition as a key determinant of overall efficiency, together with strategic use of compensatory growth, was also highlighted as an important component in improved profitability. At the same time, the beef industry needs to be more mindful of important environmental, welfare and food safety/traceability issues if it is to achieve increased productivity and industry resilience. “Between 1977 and 2007, the US beef industry produced 12% more beef from 30% fewer cattle, used 19% less feed and left a 16% reduction in the estimated carbon footprint,” according to Prof. Alan Bell.

Reflecting on the high energy costs of current animal production systems and the need to reduce carbon and water footprints of livestock production systems, urgent change in the way the diets are prepared and fed is called for. The ethics of feeding high levels of grains to ruminants has to be challenged due to food-feed competition and the impact of this practice on animal health and welfare, given that the rumen can digest fibrous feeds and is not physiologically suited to high grain usage. Towards the future, a significant number of changes in practices need to be considered, including the potential to reduce grain in livestock diets, the use of locally available feeds, respecting land diversity and amenity value, and ensuring production systems are socially equitable. The importance of developing sustainable animal diets through a conceptual framework that allows the integration of sound management practices based on the 3 Ps of sustainability (Profits, People and the Planet) was considered a prudent path for the future.

A vast proportion of the world’s dairy and beef herds are operating at suboptimal levels of efficiency with respect to the conversion of feed into human food. A reappraisal of feeding practices, based on the importance of the rumen and the provision of physical fibre in the ration for optimal digestion of feed in the rumen and improved feed efficiency is required. Currently the world produces 700 million tonnes of milk/year with an estimated total feed requirement of 1100 million tonnes (dry matter). “Through improved nutrition it would be possible to produce the same amount of milk from almost 240 million tonnes less feed use, so releasing over 20 million ha for non-dairying purposes or an increased annual production of 190 million tonnes milk at no extra feed cost,” was the opinion of Prof. David Beever.

The importance of FCE to produce more food with lower emissions per unit feed used needs to be recognized, with strategies incorporating new forage types, the importance of physical as well as chemical nutrition (to optimize rumen function) and improved cow management.
Productivity and efficiency gains move largely in parallel. The efficiency of ruminant production systems is affected by factors other than feed efficiency including the effects of endemic diseases, inadequate access of smallholders to information, technologies and well-ordered markets, and overall poor management. A holistic approach that addresses animal nutrition, animal reproduction, animal health and welfare and overall management is required for increasing FCE.

Research on feed efficiency needs to be designed in the context in which it will be applied, taking into account the market demand for products as well as the constraints within farming systems. Such an approach benefits from discussion between multiple disciplines (e.g. socio-economic as well as nutrition) at the design stage, as well as discussion with those working in the field and familiar with opportunities for livestock systems to evolve.

Research effort should be focused on tackling more applied aspects of ruminant production, with the full and collaborative engagement of both public and private bodies and the adoption of smart engineering and computerized technologies wherever deemed appropriate. There is a need to address issues of food, health and environmental security and for all sectors of the industry to work together to develop strategies and generate information to assist policymakers. Future applied nutrition research should focus on novel approaches to the development and utilization of forages and byproducts/co-products that do not compete directly with food for humans. This could include the development of crops with higher levels of digestible fibre, stressing that the future of ruminant feeding is likely to see an increasing substitution of forages with fibre-rich co-products, and cereals replaced by high sugar forages, molasses and cereal brans.

In summary, the future prospects for systems of ruminant production are encouraging but less grain will have to be fed, so opening the opportunity to feed more forages and take advantage of the increasing stream of co-product feeds. Whilst there has been discernible progress towards controlling the contribution of ruminants to global warming, the importance of optimizing the conversion of feed into food has to be better recognized, accepted and developed. Full engagement of all sectors of society will be needed if the world is to meet its challenging food and environmental demands, alleviate hunger, and avoid compromised human security, massive population displacement and weakened global trading economies. On the technical front large observed gaps between actual and attainable nutrient use efficiencies can be narrowed by improved application of existing technologies, suitable refinement of some of these and development of novel ones.

It is intended that, after completing the peer review process, the full papers will be available at FAO website in early 2013.